Indication of clear aligners in the early treatment of anterior crossbite: a case series

Effectiveness of clear aligner versus removable inclined plane in treatment of anterior crossbite in mixed dentition: A randomized clinical trial

BACKGROUND

This study aimed to compare the efficacy of clear aligners and removable inclined planes (RIP) in management of anterior crossbite in late mixed dentition patients using a 3D digital model.

MATERIALS AND METHODS

Twenty-four patients with functional anterior crossbite, aged 8 to 12 years old, were randomly assigned to two parallel groups: the clear aligner (CA) group with a mean age of 10.74 ± 1.1 years, treated with clear aligner, and the RIP group with a mean age of 10.54 ± 1.06 years. Digital models were obtained for each patient before (T0) and after 4 months of starting the treatment (T1) using an intraoral scanner. The T0 to T1 digital model was superimposed to assess the primary outcome, labial movement of the maxillary incisors. For each model, the following secondary outcomes were evaluated: overbite, intermolar width (IMW), incisor leveling, arch perimeter (AP), and mesiodistal angulation. Data analysis included descriptive statistics, paired t tests, independent t tests, one-way ANOVA, and Tukey's HSD test.

RESULTS

There was no significant difference between CA and RIP groups regarding overjet, overbite, incisor leveling, and mesiodistal angulation of the maxillary incisors (P < 0.05). However, a significant difference was found between two groups in IMW, AP, and incisor superimposition (P < 0.05).

CONCLUSIONS

The CA group showed a more significant increase in labial movement of maxillary incisors, IMW, and AP compared to the RIP group. However, both treatment protocols were effective in treating anterior crossbite. This study was recorded in the ClinicalTrials.gov database (identifier: NCT06015386).

Impact of Invisalign® first system on molar width and incisor torque in malocclusion during the mixed dentition period

In orthodontic treatment of patients during the mixed dentition period, arch expansion and opening deep overbite are one of the objectives to achieve proper alignment of the teeth and correction of sagittal and vertical discrepancies. However, the expected outcomes of most therapeutic regimens are not clear, making it impossible to standardize early treatment effects. Therefore, this study was designed to evaluate the impact of the Invisalign® First System on the dental arch circumference and incisor inclination in patients during the mixed dentition period. A total of 21 children during the mixed dentition period (10 females and 11 males, with an average age of 8.76 years) were included in this study. The patients received non-extraction treatment through Invisalign® First System clear aligners, and no other auxiliary devices were used except Invisalign® accessories. Subsequently, the cooperation degree of patients during treatment and the oral measurement parameters at the beginning (T1) and the end (T2) of treatment were collected. All patients showed moderate/good cooperation degree during treatment. Besides, horizontal width of the maxillary first molar increased significantly; the designed arch expansion was 4.1 mm (±1.4 mm), while the actual arch expansion was 3.0 mm (±1.7 mm). Furthermore, the torque expression rate of upper anterior teeth reached 56.53%. Invisalign® First System clear aligners can effectively correct the teeth of patients during the mixed dentition period, widen the circumference of dental arch, and control the torque of incisors.

Predictability of tooth rotations in patients treated with clear aligners

Clear aligners are employed daily for the treatment of several malocclusions. Previous clinical studies indicated low accuracy for the correction of tooth rotations. The aim of this study was to evaluate the predictability of tooth rotations with clear aligners. The sample comprised 390 teeth (190 mandibular; 200 maxillary), measured from the virtual models of 45 participants (21 men, 24 women; mean age: 29.2 ± 6.6 years old). For each patient, pre-treatment (T0) digital dental models (STL files), virtual plan (T1) and post-treatment digital dental models (T2) of both the mandibular and maxillary arches were imported onto Geomagic Control X, a 3D metrology software which allows angular measurements. Rotations were calculated by defining reproducible vectors for all teeth in each STL file and superimposing both T0 with T1 to determine the prescribed rotation, and T0 with T2 to determine the achieved rotation. Prescribed and achieved rotations were compared to assess movement's accuracy. The Wilcoxon signed-rank test and paired t-test were used to assess differences between the prescribed and achieved movements (P < 0.05). The overall predictability of rotational movement was 78.6% for the mandibular arch and 75.0% for the maxillary arch. Second molar accuracy was the lowest in both arches. Clear aligners were not able to achieve 100% of the planned movements.

Clear Aligners in Pediatric Dentistry: A Scoping Review

Today not just adults but also children are affected by their looks and appearance. Their facial and dental appearance primarily influence how they present themselves in the outside world. Poor esthetic appearance at any age, especially when it comes to children, affects their psychological status. In earlier times, correction of dentition used to be done with crude methods, after which came the concept of braces, which were fixed on the labial surfaces. Even with these, the patients are equally concerned with their looks throughout the treatment, and thus neither adults nor children are eager to use the standard metallic-looking orthodontic gear. To tackle this problem, researchers have developed several solutions, and clear aligners are the modern and aesthetic answer. For effective tooth movement into the desired position, thin, transparent, plastic aligners known as invisible aligners are used, which are created using the computer-aided design/computer-aided manufacturing (CAD-CAM) technology. These aligners are analogous to the splints that cover the clinical crowns as well as the marginal gingiva. The treatment requires proper patient motivation as there can be poor compliance by patients. However, it can offer greater dental hygiene, comfort, and an excellent aesthetic experience during treatment. This review highlights the history of fabrication of clear aligners, examining the efficacy, advantages, and disadvantages of transparent aligners for pediatric patients and also dentists. It weighs aspects like aesthetic appeal, comfort, oral hygiene, treatment predictability, and practice efficiency when comparing transparent aligners, like Invisalign, to conventional orthodontic treatments. It also ascertains the applicability and worth of clear aligners in contemporary orthodontic practice, while examining patient happiness, compliance, and overall treatment results.

Clear Aligner Therapy: Up to date review article

The advantages of Clear Aligners Therapy (CAT) include the braces being virtually invisible, comfortable to wear, and removable for eating and brushing; that way, CAT can be used to treat a wide range of orthodontic issues. In 1999, the company Align Technology introduced the frst commercial clear aligner system called Invisalign. The Invisalign system was initially only available to orthodontists, but later became available to general dentists as well. The system quickly gained popularity among patients who were looking for a more discreet and comfortable alternative to traditional braces. In 2000, Align Technology received FDA clearance for the Invisalign system, which further increased its popularity. The biomechanics of clear aligners involve the use of custom-made tooth aligners that are specifcally shaped to guide teeth into desired positions. These aligners are typically made from flexible materials such as polyurethane or ethylene vinyl acetate and are adjusted to apply the necessary forces for tooth movement. Attachment devices, such as power ridges or buttons, are often used to enhance or assist in specifc tooth movements and for retention of the aligner. The use of attachments allows for the exertion of desired force on the teeth, which is crucial for the success of Clear Aligner Therapy. CAT should be used if patients are concerned about the esthetic appearances of their teeth-for example, actors and other individuals that rely on their appearances in public in a professional context-and if the misalignment is not severe, so that clear aligners can still work. One should not use CAT in cases of severe crowding or spacing issues that require extractions. If the patient has complex jaw discrepancies or skeletal issues or if teeth need to be moved extensively in multiple directions, CAT is likely not going to be strong enough. In conclusion, Clear Aligner Therapy is a safe, effective, and convenient orthodontic treatment option that offers patients a virtually invisible way to achieve a straighter, more beautiful smile. With continued advancements in technology and a growing body of research supporting its effectiveness, the future of Clear Aligner Therapy looks bright.

Dimensional changes in the palate associated with Invisalign First System: a pilot study

OBJECTIVES

To compare palatal dimensions and molar inclinations after Invisalign First System (IFS) to those in patients treated with slow maxillary expansion (SME) and normal controls.

MATERIALS AND METHODS

Twenty-three mixed dentition patients treated with IFS were gender- and dental age-matched to another two groups: Haas-type SME and control group. The intercanine width (ICW), intermolar width (IMW), palatal surface area (SA), volume (V), and first molar buccolingual inclinations (MI) were measured before (T1) and after (T2) treatment. Analysis of variance was used to compare the differences among the three groups.

RESULTS

The ICW increased significantly by 3.10 mm after IFS, 4.77 mm with SME, and 0.54 mm in controls; the difference among the groups was statistically significant (P < .001). The IMW increased by 1.95 mm in IFS, 4.76 mm in SME, and 0.54 mm in controls, with significant intra- and intergroup differences. Palatal SA and volume increased by 43.50 mm2 and 294.85 mm3 in the IFS group, which differed significantly from SME, but was similar to controls. The right and left MI increased 0.24° and 0.08° buccally, respectively, in the IFS group, which was comparable to controls, while significantly increased buccal MI was observed in the SME group.

CONCLUSIONS

IFS expands the upper arch with increased ICW and IMW compared to controls, but the expansion amount is smaller than SME. Unlike SME, IFS has no effects on palatal dimensions and molar inclinations.

Clear aligner therapy in the mixed dentition: Indications and practitioner perspectives

INTRODUCTION

This study evaluated current trends and perspectives among orthodontists regarding clear aligner therapy in the mixed dentition (CAMD), including insights into perceived indications, compliance, oral hygiene, and other factors.

METHODS

An original, 22-item survey was mailed to a randomized, nationally representative sample of practicing orthodontists (n = 800) and a specific, randomized subsample of high-aligner-prescribing orthodontists (n = 200). Questions assessed respondents' demographic information, experience with clear aligner therapy, and perceived advantages and disadvantages of CAMD compared with fixed appliances (FAs). Responses were compared using McNemar's chi-square and paired t tests to assess CAMD vs FAs.

RESULTS

One thousand orthodontists were surveyed, and 181 (18.1%) responded over 12 weeks. CAMD use was less common than mixed dentition FAs, but most respondents predicted an increase in their future CAMD use (57.9%). Among respondents using CAMD, the number of patients with mixed dentition treated with clear aligners was significantly lower than the number of total patients with clear aligners (23.7% vs 43.8%; P <0.0001). Fewer respondents considered skeletal expansion, growth modification, sagittal correction, and habit cessation feasible indications for CAMD compared with FAs (P <0.0001). Perceived compliance was similar for CAMD and FAs (P = 0.5841), but perceived oral hygiene was significantly better with CAMD (P <0.0001).

CONCLUSIONS

CAMD is an increasingly common treatment modality for children. Most surveyed orthodontists reported limited indications for CAMD compared with FAs but perceived noticeable benefits for oral hygiene with CAMD.

The Predictability of Transverse Changes in Patients Treated with Clear Aligners

Arch expansion might be used to correct buccal corridors, improve smile aesthetics, resolve dental cross bite, and gain space to resolve crowding. In clear aligner treatment, the predictability of the expansion is still unclear. The purpose of this study was to evaluate the predictability of dentoalveolar expansion and molar inclination with clear aligners. In the study, 30 adult patients (27 ± 6.1 years old) treated with clear aligners were selected (treatment time: 8.8 ± 2.2 months). The upper and lower arch transverse diameters were measured for canines, first and second premolars, and first molars on two different sides (gingival margins and cusp tips); moreover, molar inclination was measured. A paired t-test and Wilcoxon test were used to compare prescription (planned movement) and achieved movement. In all cases, except for molar inclination, a statistically significant difference was found between achieved movement and prescription (p < 0.05). Our findings showed a total accuracy of 64% for the lower arch, 67% at the cusp level, and 59% at the gingival level, with a total accuracy of 67% for the upper arch, 71% at the cusp level, and 60% at the gingival level. The mean accuracy for molar inclination was 40%. Average expansion was greater at cusps of canines than for premolars, and it was lowest for molars. The expansion achieved with aligners is mainly due to the tipping of the crown rather than bodily movement of the tooth. The virtual plan overestimates the expansion of the teeth; thus, it is reasonable to plan an overcorrection when the arches are highly contracted.

Clear Aligners Treatment of Class III Subdivision with an Extraction of a Lower Bicuspid

The aim of this study was to show a case of a Class III subdivision adult patient treated with clear aligners (CA) and the extraction of a lower bicuspid. A 19-year-old male with a class III canine and molar relationship on the right side and a deviation of lower dental midline to the left asked for an aesthetic treatment. He refused orthognathic surgical procedures, so he was offered a camouflage orthodontic treatment with the extraction of lower right first premolar to achieve a canine Class I relationship and to center the lower midline. The treatment was performed with clear aligners and the use of Class III elastics to maintain distal anchorage on the right side during the canine distalization. At the end of the treatment, the occlusal objectives were achieved.

Upper arch dimensional changes with clear aligners in the early mixed dentition : A prospective study

BACKGROUND

One goal of orthodontic treatment in mixed dentition is to expand the maxillary arch to allow proper tooth alignment and a correction of sagittal and vertical malocclusions. However, for most treatment protocols, expected outcome is not really clear to allow for a standardization of phase I orthodontic treatments. This lack of information makes it difficult for clinicians to predict tooth movements, including transverse expansion efficacy with Invisalign® (Align Technology, Santa Clara, CA, USA) in children. Therefore, the aim of the present study was to evaluate the transverse maxillary arch development with the Invisalign First System® in growing subjects.

METHODS

The study group included 23 subjects (9 females, 14 males, mean age 9.4 ± 1.2 years). Patients were treated nonextraction with Invisalign First System® clear aligners with no auxiliaries other than Invisalign® attachments. Transverse interdental widths were measured only in the upper arch on each model at the start (T1) and at the end (T2) of treatment. A paired t‑test was chosen to compare T2-T1 changes. The level of significance was set at 5%.

RESULTS

The greatest increase of maxillary width was detected at the level of the upper first deciduous molars (+3.7 ± 1.4 mm; P < 0.001), followed by the level of the second deciduous molars (+3.4 ± 1.6 mm; P < 0.001) and by the deciduous canine (+2.6 ± 2.0 mm; P < 0.001). Upper first molars showed a greater expansion in the intermolar mesial width (+3.2 ± 1.2 mm; P < 0.001) than in the intermolar distal (+1.7 ± 1.2 mm; P < 0.001) and transpalatal width (+1.2 ± 1.2 mm; P < 0.01).

CONCLUSIONS

The Invisalign First System® can be considered effective in growing patients who require maxillary arch development. The greatest net increase was detected at the level of upper first deciduous molars, whereas the upper first molars showed a greater expansion in the intermolar mesial width due to a rotation that occurs around its palatal root.

Gingival Margins' Modifications during Orthodontic Treatment with Invisalign First®: A Preliminary Study

The aim of the study was to assess modifications of gingival morphology at the end of Phase I treatment with Invisalign First. Eighteen subjects (ten females, eight males, mean age nine years) treated with Invisalign First were selected. The following parameters were measured on intraoral photographs before treatment (T0) and after the first set of aligners (T1) at level of permanent incisors, deciduous canines and molars: gingival margin height (GMH) and deciduous canine inclination (DCI). A paired t-test was used to evaluate T1-T0 changes. The level of significance was established at 5%. Deciduous canines' GMH showed a major reduction between T1 and T0 accounting for 0.87 mm and 0.86 mm, respectively on the right and left sides. DCI increased for all patients in the interval T0-T1 on both sides, +7.11° on the right and +7.5° on the left. Tooth movement during Invisalign First induced significant modifications of gingival contour resulting in a more harmonious smile.

Evaluation of the Upper Arch Morphological Changes after Two Different Protocols of Expansion in Early Mixed Dentition: Rapid Maxillary Expansion and Invisalign® First System

Background: The objective of this retrospective study was to analyze the morphological changes of the upper arch after two protocols of expansion, the Invisalign® First system and rapid maxillary expansion (RME), in mixed dentition by means of geometric morphometric analysis (GMM). Methods: Digital dental casts of 32 children treated either with RME (RME group: 17 subjects; mean age 8.1 years) or the First system (First group: subjects; mean age 8.4 years) were collected. For both the RG and FG, pre-(T1) and post-treatment(T2) digital models were created. A total of 14 landmarks were digitized and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed. Results: The PC1 resulting from the T2–T1 comparison in the RG g showed statistically significant morphological changes in the posterior region of the upper arch shape, without significant variations in the anterior region. The comparison of the T2–T1 changes in the FG showed an increase in the transverse dimension at the level of the canine and the first deciduous molar widths, with morphological variation in the anterior region due to frontal teeth alignment. Conclusions: The First system induced shape modifications of the upper arch during expansion in contrast to RME. The FG presented an improvement in the maxillary arch shape, while the RG maintained the initial triangular shape.

Clear Aligners: Between Evolution and Efficiency-A Scoping Review

In recent years, clear aligners have diversified and evolved in their primary characteristics (material, gingival margin design, attachments, divots, auxiliaries), increasing their indications and efficiency. We overviewed the brands of aligners used in Italy and reviewed the literature on the evolution of clear aligners based on their characteristics mentioned above by consulting the main scientific databases (PubMed, Scopus, Lilacs, Google Scholar, Cochrane Library). Inclusion and exclusion criteria were established. The data were collected on a purpose-made data collection form and analyzed descriptively. From the initial 580 records, 527 were excluded because they were not related to the subject of the review or because they did not meet the eligibility criteria. The remaining 31 studies were deemed comprehensive for the purpose of the review, although the “gingival margin design” feature and “auxiliaries” tool are not well represented in the more recent literature. Current knowledge on invisible aligners allows us to have a much clearer idea of the basic characteristics of aligner systems. There remains a need to deepen the use of systems other than Invisalign™ to give greater evidence to aligners that are very different based on the characteristics analyzed here and that are very widespread on the market.

Radiographic Assessment of Pediatric Condylar Fractures after Conservative Treatment with Functional Appliances-A Systematic Review

BACKGROUND

To evaluate the effectiveness of conservative treatment with functional appliances for condylar fractures in pediatric age.

METHODS

Four electronic databases (PubMed, EBSCO, Scopus, and Web of Science) were consulted with no restriction of publication status or year, up to 31 August 2020.

SELECTION CRITERIA

based on the PICOS criteria, the selection criteria were set for observational human studies, with at least 10 patients and six months of follow-up. The study population included pediatric patients (aged 5-16 years), with unilateral or bilateral condylar fracture, treated with functional appliances. Condylar remodeling and mandibular growth were analyzed through sequential radiographic examinations.

DATA COLLECTION AND ANALYSIS

Two independent reviewers carried out title-abstract screening, and a senior investigator was involved to solve any disagreement. The quality of the evidence was assessed through the Canada Institute of Health Economics (IHE) quality appraisal checklist, and the National Institutes of Health (NIH) quality assessment tool.

RESULTS

A total of 971 articles were retrieved from the electronic search; among them, three studies met the eligibility criteria. A moderate risk of bias was detected in all the studies, due to common limitations (absence of multicenter studies, prospective design, blindness of the investigators, patients' drop-out). At follow-up examinations (between 6 months and 4.9 years), the difference of condylar neck length between the "injured" and "healthy" side was approximately 2 mm, while the anteroposterior condylar width discrepancy was recorded up to 1 mm.

CONCLUSIONS

Short- and long-term data revealed that conservative treatment with functional appliances led to partial or full radiological recovery of the joint morphology, along with good to excellent functional results. Patients' age has a crucial role on the treatment choice, and the type of fracture (presence of condylar displacement, or dislocation) is also a major prognostic indicator of the radiologic outcome.

LIMITATION

To confirm the effectiveness of functional appliances, more prospective clinical long-term follow-up studies with homogeneous samples of condylar fractures are deemed necessary. Registration: The study protocol was registered on PROSPERO (CRD42020205650).